1. Field of the Invention
The present invention relates to a semiconductor device including a plurality of chips. The present invention also relates to a method of manufacturing a semiconductor device.
2. Description of the Related Art
Conventionally, a power device such as a power metal-oxide semiconductor field-effect transistor (power MOSFET) and an insulated gate bipolar transistor (IGBT) is used for driving a load such as a motor. In a case where a full bridge circuit is assembled from power devices for driving a motor, four power devices are required for driving a brush motor and six power devices are required for driving a brushless motor. Thus, when a plurality of power devices is formed on one plane of a chip or when a plurality of power devices is formed on respective chips and the chips are arranged on one plane, a dimension of a substrate is difficult to be reduced.
US 2007/0075419 A (corresponding to JP-A-2007-73674) discloses a semiconductor device that includes a metal frame functioning as a drain electrode and a plurality of vertical power devices formed on a front surface and a rear surface of the lead frame. In the semiconductor device, the vertical power devices and the lead frame are stacked. Thus, a dimension of a substrate can be reduced.
However, in the above-described semiconductor device, the lead frame is disposed between respective semiconductor elements. Thus, a mounting dimension may be increased.